Scanner->ASB->IT8_card_BTRs

We are in trouble!! had AB at the site....

The IT8 thermocouple/mV card hangs and does not up date the current raw data. The book calls to config with BTW and to read with BTRs. The BTRs always are reading through the scanner card with no errors. There are 10 IT8 cards on the flex I/O with discrete I/O and several ASB cards. All the ASBs green lights are OK. The individual IT8 OK lights are fine.
The problem is that the raw data in the registers after the BTR reads will hold a last value and never update what is at the card, the discrete I/O will be fine. But the values coming through the M1:1.XXX will be locked at a value and unless you reconfigure the card with a BTW to disable all channels and then another BTW for the real configuration, the cards will lock the data on all the channels forever. The ladder is right from the text book there are 10 BTRs in yhe ladder, no register overlap found. Any help....???

You may have to multiplex the BTR's. What processor and comm link are you using. We had to multiplex the BTR's with a CLX procesor using Remote I/O as the comms link

It is a SLC505 .

Can you post your .rss file? If not the entire file, can you post a snippet showing a couple of the BTR's. Each BT requires a false to true transition to reset all the control/status bits.

FYI the block transfer buffer occupies both the M1 and M0 files, so if you use buffer M0:e.100 for a BTW you cannot use M1:e.100 for a BTR. The Scanner has 32 buffers, so you should be able to configure 16 reads, and 16 writes.

To ensure the RIO buffer is not overloaded, I usually cascade my Block transfers.

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